Recording a Slinky Blaster Sound Effect

I was quite surprised when I first learned that many of the cool blaster sounds in sci-fi movies were created with stretched springs, including the slinky, and have always wanted to try it. So the other day I gathered up a few students, a slinky, and a very tall mic stand, and set about creating a slinky blaster sound.

Setting up the Slinky blaster rig

The setup is pretty straightforward: hook one end of the slinky over the top of the mic stand, and attach the other end to the stand’s base with a small piece of gaffer’s tape. If you try this yourself, you may be a bit underwhelmed by the sound the slinky makes. It sounds like a blaster, but it’s very quiet. You’ll also find that there are a lot of variables that affect the sound – how hard you hit the slinky is a big factor. Don’t hit it too hard – it might rattle:

Getting the Slinky Blaster sounds just right

Because the slinky is so quiet, the room you record in needs to be very quiet, and you do too. The recording studio at the Madison Media Institute is very quiet, so it wasn’t an issue. I was though, you can hear me shifting my feet in the decay of this clip:

What you hit the slinky with is also important. A screwdriver works well. The angle you hit the slinky at matters too – you’ll just have to experiment. We also found that you need to stretch the slinky quite a bit – we ended up with it extended to at least ten feet. All in all, we ended up recording about 10 minutes of slinky hits, using two Neumann Km-84 mics, the stock preamps in our SSL-4000 console, and Pro Tools 11. Here are five hits culled from about a hundred we recorded. The only processing at this point is a bit of EQ to filter out the low-end rumble:

Not too bad, but still a little underwhelming. Time to dig in with Pro Tools and see what we can come up with. The sound dies out pretty quickly – how about putting a really heavy limiter on it:

That’s interesting, but it really brings out the noise. Izotope makes some amazing noise removal software. Here are the same five hits after tweaking with RX4:

Getting better, but still not quite there. We decided to try a little time stretch, to make the sounds last a little longer:

That’s starting to sound pretty cool, but there’s a bit of springy slinky rattle at the start of each hit. Usually, we think of a de-esser as a tool to control vocal sibilance, but it can come in handy in unexpected situations. Here’s how the blaster sounds de-essed

And finally, a little more EQ to focus the “bewww” part of the sound and a touch of tape echo to give it some depth:

There you have it – a slinky blaster, or at least one way to do it. There are plenty of other ways to create similar sounds – any hardware store has all sorts of springs and other potential sound generators on hand. The only limit is your knowledge and creativity... Sound interesting? This is what you can experience in our Recording and Live Sound program. Come join the fun.